(1).select
显示当前日期和时间
mysql> select now();
+---------------------+
| now() |
+---------------------+
| -06-05 13:46:20 |
+---------------------+
1 row in set (0.00 sec)
显示当前日期
mysql> select curdate();
+------------+
| curdate() |
+------------+
| -06-05 |
+------------+
1 row in set (0.04 sec)
显示当前时间
mysql> select curtime();
+-----------+
| curtime() |
+-----------+
| 13:48:15 |
+-----------+
1 row in set (0.00 sec)
显示当前所在数据库
mysql> use test_db;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| test_db |
+------------+
1 row in set (0.00 sec)
显示Mysql版本
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.16 |
+-----------+
1 row in set (0.00 sec)
显示当前用户
mysql> select user();
+----------------+
| user() |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)
(2).show
show variables;显示变量
show global variables;显示全局变量
show global variables like '%version%';显示版本信息
mysql> show global variables like '%version%';
+-------------------------+------------------------------+
| Variable_name | Value |
+-------------------------+------------------------------+
| innodb_version | 5.7.16 |
| protocol_version | 10 |
| slave_type_conversions | |
| tls_version | TLSv1,TLSv1.1 |
| version | 5.7.16 |
| version_comment | MySQL Community Server (GPL) |
| version_compile_machine | x86_64 |
| version_compile_os | Linux |
+-------------------------+------------------------------+
8 rows in set (0.00 sec)
show variables like '%storage_engine%';显示默认的存储引擎
mysql> show variables like '%storage_engine%';
+----------------------------------+--------+
| Variable_name | Value |
+----------------------------------+--------+
| default_storage_engine | InnoDB |
| default_tmp_storage_engine | InnoDB |
| disabled_storage_engines | |
| internal_tmp_disk_storage_engine | InnoDB |
+----------------------------------+--------+
4 rows in set (0.00 sec)